Transmission electron micrographs of samples from date palm root tissues infected by Fusarium oxysporum f. sp. albedinis (Foa). A: Preserved cell wall (CW) in control (non-
infected plants). B: Root tissues colonization is associated with primary wall alteration and middle lamella dissolution. C: Complete disruption of the cell wall as well as cytoplasm
alteration and presence of undamaged fungal hyphae. D: Polymorphic deposits (PD) in parenchyma cells. E–F: 2 weeks after inoculation, parenchyma cells in cortex show retraction
of plasmalemma and accumulation of electron dense material along the tonoplast vessels, a coating material accumulates along the secondary walls extends to form osmiophilic
droplets (OD). G: Phenolic-storing cell (PhC) observed 1 week after inoculation, around and in vascular stele of root. Scale bars represent 1 mm (G plate); 2 mm (C plate); 100 nm
(E plate); 200 nm (A, B, F plates) and 500 nm (D plate)